First Advisor

Donald G. Howard

Term of Graduation

Summer 1971

Date of Publication

8-17-1971

Document Type

Thesis

Degree Name

Master of Science (M.S.) in Physics

Department

Physics

Language

English

Subjects

Aluminum -- Analysis, Cobalt, Mössbauer effect

DOI

10.15760/etd.1476

Physical Description

1 online resource (ii, 47 pages)

Abstract

Using Fe57Mössbauer spectroscopy, two alternative sites occupied by cobalt (10-4 at. % ) impurity atoms in aluminum have been isolated. The substitutional site A is the stable position after annealing the sample above 840 K, followed by a rapid quench. The impurity atoms in site A are characterized by a single line Mössbauer spectrum (indicative of a cubic environment), a room-temperature f = 0.502 (r. m. s. displ. 0.071 A) and an I. S. (reI. to Fe) = -0.421 mm/sec. For anneals below 770 K the cobalt atoms migrate to site B, which is characterized by a well resolved quadrupole doublet (indicative of a non-cubic environment), a large change in the value of the room-temperature f = - 0.766 (r. m. s. displ. 0.071 A), I. S. = -0.150 mm/sec (increased s-electron density at the nucleus). All linewidths are approximately 0.21 mm/sec, indicating high uniformity of impurity sites. The site distribution [A] / [B] varies from about 5 % to 95 % for anneals between 770 K and 830 K.

Rights

In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

Comments

If you are the rightful copyright holder of this dissertation or thesis and wish to have it removed from the Open Access Collection, please submit a request to pdxscholar@pdx.edu and include clear identification of the work, preferably with URL.

Persistent Identifier

https://archives.pdx.edu/ds/psu/10221

Download

Share

COinS